The shock-wave synthesis of ultradisperse chromium-doped alumina powder

An ultradisperse alumina (Al2O3) powder doped with Cr3+ ions was synthesize d for the first time by shock-wave loading of a mixture of aluminum powder and ammonium chromate. The synthesized powder is composed primarily of the chromium-doped alpha- and delta -Al2O3 particles. The luminescence spectra of the alpha phase are identical to those of a macroscopic ruby crystal sam ple, which indicates that chromium atoms are incorporated into the alumina lattice. The Cr3+-doped delta -Al2O3 modification represents a new optical material. (C) 2001 MAIK "Nauka/Interperiodica".